By all accounts i probably look like biz traveler, even when on leisure. I don't find jeans comfortable to fly in, so I'm usually wearing slacks and I love the convenience (think pockets), and quite frankly the look, of a sport coat and open throat button down--it suits me (no pun intended). For overnight flights, I usually pack pjs in my carry-on.

I remember, as a kid, my dad telling me that someday I'll discover that nice, properly fit "dress up" clothes are the most comfortable thing around. He was correct.

Regarding other comments about dress being irrelevant to the conduct of business...there are far too many variables to make such a statement. Perhaps in your particular line of work, at your level and/or with whom you deal, that is true , however the sentiment is not universal.

Edited to add:
I tend not to make serious value judgments on one's attire, however it does enter the calculus that makes up ones entire demeanor. I've encountered perfect arses that were dressed to the nines--the clothes do not make the person; tis the other way round.